The invention relates to the field of motion system actuators used for example for: flight and vehicle driving simulators. The simulators for which the invention applies are simulators comprising, for example, a real piloting or driving booth. The use of a real booth means that the simulator has a weight and a size that are both significant.
In order to maintain the simulators, reduce the cost of the infrastructures in which the simulators are placed, and the cost of the energy to be supplied to mobilize a simulator, it is increasingly commonplace to use electric motion actuators instead of hydraulic motion actuators.
One of the problems associated with the use of electric motion actuators relates to having to take into account the static forces linked to the load being displaced and the dynamic forces linked to the weight and the inertia of the load being displaced.
There are various compensation solutions available, such as: pneumatic compensation, hydraulic compensation.
A pneumatic compensation system operates notably with accumulators and a compressor. The compressor compresses a gas in the accumulators. The accumulators are elsewhere linked to an actuator or to a compensation cylinder. The pneumatic compensation system supplies a relatively constant, unidirectional force.
A hydraulic compensation system operates notably with accumulators and a hydraulic plant. The hydraulic plant compresses an oily solution in the accumulators. The accumulators are linked to the actuator. The hydraulic compensation system also supplies a relatively constant, unidirectional force.
The pneumatic and hydraulic compensation solutions have the following main defects:                they have a large ground footprint;        they are expensive to manufacture and maintain;        they are subject to pressure equipment usage standards which are highly restrictive;        they do not adapt well according to the variations of the static force applied to the actuator because the compensation force is relatively constant.Furthermore, the pneumatic compensation systems take a relatively long time to start up, adding an additional constraint to the use of the simulator.        